半导体锗纳米团簇和纳米层的生成结构与PL谱研究

在硅锗合金衬底上采用氧化等制膜方式生成零维和二维的纳米结构样品，用高精度椭偏仪(HPE)、卢瑟福背散射谱仪(RBS)和高分辩率扫描透射电子显微镜(HR—STEM)测量样品的纳米结构．并采用美国威思康新州立大学开发的Rump模拟软件进行精细结构模拟．并测量出样品横断面锗纳米团簇和纳米层的PL谱。在硅锗合金的氧化层表面中首次发现纳米锗量子点组成的几个纳米厚的盖帽膜结构．首次提出的生成硅锗纳米结构的优化加工条件的氧化时问和氧化温度匹配公式的理论模型与实验结果拟合得很好．

Nanoparticle and nanolayer in oxide film and substantial Ge segregation

We investgated the oxidation behaviors of Si1-x Gex alloys with a 0. 5% ,2%, 5%, 15% and 25% Ge content. The oxidation of SiGe films with different compositions is carried out in dry oxygen gas at 800 C , 900 C and 1000 C for various length of time. Thickness and property of nanoparticle and nanolayer in oxide films and germanium segregation in oxidation of SiGe alloys as obtained using high precision ellipsometer (HPE) show good agreement with rutherford backscattering spectrometry (RBS), profile dektak instrument (PDI) and high -resolution scanning transmission electron microscopy (HR -STEM) observation. We observed that the Ge content in the oxide layer increased with the Ge content in SiGe layers, Ge content in the oxide film decreased with the increase of oxidation temperature and with the increase of time length. Rejection of Ge results in piling up of Ge at the interface between the growing SiO2 and the remaining SiGe which forms nanometer Ge -rich layer. And substantial interdiffusion of Si and Ge takes place in the remaining SiGe which leads to the complicated distribution of Ge segregation. Several new phenomenons were discovered , and the experimental results were discussed and simulated. The oxidation optimum of SiGe has been obtained.